Press provided with at least one die for moulding products from ceramic material



3,019,505 ING Feb. 6, 1962 H. J. VAN DEN BERGE ETAL PRESS PROVIDED WITH AT LEAST ONE DIE F'OR MOULD 1=xonucws FROM CERAMIC MATERIAL 2 Sheets-Sheet 1 Filed Dec. 18, 1958 INVENTOR A N DE N BERGE 'J'*" v JOHANPES JOCHEM WILLEM GELEIJNSE ADRIANUS THEODORUS VAN DER MAAT BY A ENT Feb- 6, 1962 H. J. VAN DEN BERGE ETAL 3019505 PRESS PROVIDED W LEAST ONE DIE FOR MOULDING PRODUCT CERAMIC MATERIAL Filed Dec. 18, 1958 2 Sheets-Sheet 2 JOHANNES JOCHEM WILLEM GELEIJNSE ADRIANUS THEODOR' VAN DER MAAT United States Patent O 3,019,505 PRESS PROVILDED WTH AT LEAST ONE DIE F R MULDNG RDUCTS FROM CERAMIC M- 'EERIAL Hendrik Jan van den Berge, Nico Biiek, Johannes Jochem Willem Geieijnse, and Adrianus Theodorus van der Maar, aii of Eindhoven, Netherlands, assignors to North American Phiiips Cmnpnny, Inc., New York, N.Y., a corporation of Delaware Fiied Dec. 18, 1958, Ser. No. 781,298 Ciaims prioriy, appiieaon Neheriamls Jan. 3, 1958 8 Claims. (Cl. 25-45) This invention relates to presses for moulding products from ceramic maeriai.

Accordin to the invention, such a press is characterized in that it contains a duet through which the ceramie material is fed to the die 01 dies as a suspension in a liquid preferably having a 1ow viscosity, rneans being provided for the diseharge of the liquid d-u-ring the pressing process. Feeding the material and iilling the dies is materialiy facilitated by the use of the invention and furthermore ether difliculties such, for exarnpie, as the formation of cloucs of dust of the finely divided or pulverized material are avoided. Since in accordance with the invention special means are provided for drawing ofi? the liquid during the rnouiding process, the punches may accurately iit in the dies,

According to one embodrnent of the invention provision is made of at least one die open at -two ends which during the moulding operation is closed at one end by a punch and at the other end by a filter. This embodment of the invention provides the advantage that the moulded articies can readiiy be taken out since after the rernoval of he filter or filters they can be pressed out of the die er dies by a further movernent of the punch or punches. In a further embodiment of the invention the filter corn prises -a perforated plate provided with a poreus cover.

in a still urther embodiment of the invention provision is made of at least (me die open at two ends which is closed on both sides by rn0vable punches which have, at least at one side, discharge ducts for the suspension iiquid which are closed by a poreus cover. In some cases the discharge of the suspension liquid is facilitated and accelerated by this embodrnen of the inventon.

In anoher ernbodiment of the invention he punches are secured to a pressing piunger which is provided with a duet which extends in the direction of lengh of the piunger and is provided with a check vaive and through which the suspension is periodicaiiy fed to the dies. Thus, the use of resilient means for feeding the suspension to the dies is minimized While the construction of the device is simplified.

In still another embodiment of the invention the press inciudes a reciprocating closing member containing -a. duet for discharging the suspension liquid, and furthermore a rnouiding plaie adapted to be moved in the same directions and provided with at least one preferaby ex ehangeable die, the filter being arranged befiween the closing member and the rnouiding piate, while the likewise reciprocating pressing plunger, which carries the punches, passes through the mouiding p1ate in a liquid-tight manner. This ernbodiment of the press has the advantage that the filter can readily be replaced when it is elogged, while the dies a-re sealed on one side in a sirnpie manner and furtherrnore the mouided products are readily accessible.

In a further ernbodiment of the invention the press is preferably designed so that between the side of the dies acing the piunger seal and this seai there is a space in whch the pnnches can be accommodated entirely, "rhe surfaces of the upper sides of the punches when projected onto a piane at right angles to the plunger centre line together being about equal '10 the cross seotional area of the plunger. The advantage of this embodiment consists in that the dies are fiiled more satisfactorily and furthermore the suspension does not seep between the punches and the die waii since the volume of the suspension remains substantially constant.

It is known to subject ceramic material to the influence of a magnetic field during a moulding operation. The press in accordance with the present invention is particularly suited for carryng out this method, if, in accordance with a further embodiment of the invention, the dies are made of a non-maguetizable maten'al while coils wh.ich in operation pass an eleotric current, are arranged in the closing rnember surrounding the dies so that the ceramic material is subjected to the influence of a. magnetic field during the moulding process.

In order that the invention may readiiy be carried out, au embocliment thereof will W be described, by way of exarnpie, with reference to the accompanying drawings, in whch FG. 1 is a cross-sectionai view of a hydraulic press taken along a vertical plane,

FIG. 2 is a crosssectional view taken along the line 22 of FI G. 1, and viewed in the direction of the arrows, and

FIG. 3 shows diagramrnatically a modified ernbodirnent of a part of the press shown in FIG. 1.

in the figures, reference numeral 1 designates 2. cylinder in which a moulding plunger 2 can move. The cylinder 1 forrns part of a frame on which cylinders 3 and plungers 4 are provided. The main plunger 2 has a cylindrical part 5 to which tw0 p=unches 6 are secured. The piungers 4 are rigidly connected to a moulding plate 7 containing an annular member 8. A vertical rm 9 of this annular member 8 embraces dies 10 and another cylindrical member 11 in which a rubber ring 12 is enclosed for sealing the plunger part 5. A space 13 is 1eit between the lower sides of the dies 10 and the seal 12. At the upper end of the press provision is made of two pressing eylinders 14 and plungers 15. These plungers 15 are secured to a closing member 16 which contains a second annular member 17. This annular member 17 encircles a plate 19 provided with apertures 18, the ciosing rnernber 16 having an aperture 20. Between the closing member 16 and the moulding plate 7 there are interposed a centrally perforated metal plate 21 and a filter '22. The main plunger 2 "and the part 5 of this plunger coutain a bore 23 and a check va1ve 23a. The eross-sectional area of the cylindrieal part 5 is abou eq11al to the sum of the surfaces of the punches 6 designated A.

At the beginning of the moulding cycle the moulding plate 7 is supported by the piungers 4 which act as hydraulc buffers and by the cylinders 3, and there is a clearance between the rnoulding plate 7 and the closing rnemoer 16. The die cavities are entirely open. Subsequently the closing member 16 together with the filter is pressed by the piungers 15 onto the moulding plate 7 and, the suspension is then fed to the dies When the supply of suspension is sufficient, the plungers 15 press the ciosing member 16 and the moulding plate further downwards, the plunger 2 still being stationary, so that the punches 6 are pressed into the die cavities and the suspension liquid is expelled. When the products have been formed in this manner, the plunger 2 rnoves upwards and by this upward movernent and by buffer acton of the plungers 4 the moulding plate 7 and the closing member 16 are also moved upwards. When a certain position is reached, the plungers 4 becorne inoperative; however, the plunger 2 continues its movement, the moulding plate 7 being stationary, and the products are pressed out of the die cavities, the closing member 16 being likewise pressed upwards. When the products are entirely pressed out of the die cavities, the plunger 2 stops; the plungers move the closing member 16 slightly further upwards so that the products can be removed. Finally the plunger 2 moves downwards and the moulding cycle can be repeated.

Obviously, by means of the described press articles can be moulded whch have a different arbitrary cross sec tion 01 are provided with tags, flanges, lugs and similar projecting pars. In this event, the dies must be designed so that these articles can be removed therefrom, for example by the use of split dies or in some ether known manner.

The entire closing plate 16 may be omitted and replaced by a second moulding plate 26, as is shown diagrammatically in FIG. 3, provision being made of a second pressing plunger 27 which is provided with apertures 28 and carries a filter 30 at the pressing end of counterpunches 29 provided on the pressing plunger 27. Thus, a moulding pressure is exerted on the suspension frorn both sides, so that the speed of the process is increased. Alternatively the punches 6 and the pressing plunger 5 may be apertured, a filter being arranged on the upper ends of the punches 5.

In the press shown, cavities 24 and 25 are provided both in the moulding plate 7 and in the closing mernber 16. Heating or cooling elements may be provided in these cavities, if this should be requred or desirable for the material to be moulded. Alternatively, coils passing an electrc current may be disposed in these cavities, the

edges of the mouldng plate 7 and theclosing member 16 and the dies being made of a non-magnetizable mate- 'rial so that the ceramic material can in a known manner be exposed to the influence of a magnetic field during the moulding process, a certain orienting influence being exerted on the suspended ceramic material.

What is clairned is:

1. A press or moulding ceramic products in a mould open on both ends comprising a plunger reciprocatng through one end of said mould, a closing member adjacent to the other end of said mould, said closing member being provided with apertures forming a complete passage through said closng member, a filter interposed between said closing member and said mould a space in said press communicating with said mold, duet means in said plunger extending longitudinally thereof and opening into said space, through whch ceramic material is fed as a lqud suspension to completely fill said space and said mold, means to move said mold to reduce the volume of said space and thereby concentrate the suspension in saiC mold prior to the moldng operation proper, said apertures being the means for discharging the lqud during said mold movement and the moulding operation proper, said mould during the moulding opera tion being closed at one end by said plunger and at the other end by said filter.

2. A press for moulding ceramic products as claimed in claim 1 wherein said filter comprises a perforated plate and a porous cover overlay.

3. A press for moulding ceramic products as claimed in claim 1 wherein said duet means is a duet whch extends the length of said plunger and including a check valve through whch said lqud suspension is fed periodically to said mould.

4. A press for moulding ceramic products in a mould open on both ends comprising a plunger reciprocating through one end of said mould, a closing member adjacent to the other end of said mould, said closing member being provided with apertures forming a complete passage through said closing member, a filter interposed between said closing member and said mould, and duet means through whch ceramic material is fed to the mould as a lqud suspenson, said apertures being the means for discharging the lqud during the moulding operation, and said mould during the mouldng operation being closed at one end by said plunger and at the other end by said filter, and a space communicatng with said mould and accommodating the head of said plunger, means to move said mold to decrease the volume of said space thereby concentrating the suspension in said mold, said plunger operatively associated with said mold to eject molded material therefrom.

5. Apparatus comprisng a press, at least one die means operatively associated with corresponding punch means at one side thereof and filter means operatively associated with said die at the other side thereof, a space in said press communicatng with the die cavities, means to fill said space and said die cavities with a solid suspenson, means to move said die te decrease the volume of said space and thereby concentrate said suspension in said cavity by orcing lqud through said filter means and means to move said punch to mold said concentrate within said die and expel the suspending lqud through said filter.

6. Apparatus according to claim 5 wherein said die is open endecl and said punch is arranged t0 pass into said die cavty whereby said molded material is ejected from the die.

7. Apparatus comprising at least one die member having an open ended die cavity, a movable mold member supporting said die member, said movable mold member defining a space communicating with said die cavity at one end of said die member, punch means cperatively associated with said space and movable relative to said mold member, movable closure means including filter means operatively associated with said die member to close the other end of said die cavity, means adapted to supply a solid suspended in a lqud to said space and said die cavity means adapted to supply a solid suspended in a lqud to said mold member in fluid tight relation and move said closure means and said mold member relative to said punch means to reduce the volume of said space and register said punch means with said die member to close the adjacent end of said die cavity whereby said die cavity is filled uncler high pressure with highly concentrated solids suspenson, means to move said punch means relative to said closure means and said mold member and into said die cavity to further compact said solids in said die cavity and substantially oompletely separate said solids and suspending lqud, said lqud being withdrawn through said filter means.

8. Apparatus according to claim 5 wherein said punch means are adapted to eject said molded materal from said die.

References Cited in the file of this patent UNITED STATES PATENTS 1,071,020 Bartholomew Aug. 26, 1913 1,918848 Land et al. July 18, 1933 1,993,047 Westman Mar. 5, 1935 2047,356 Boyle June 14, 1936 2,602,189 Finelt July 8, 1954 2,714,849 Carver Aug. 9, 1955 2,77G,025 Mollers Nov. 13, 1956 2,903329 Weber Sept. 8, 1958 FOREIGN PATENTS 568,940 France Jan. 2, 1924 

